Science Animals Including Humans

Science | Year 3 | Animals Including Humans | Types of Skeletons | Lesson 2

Aim • I can sort animals based on their skeletons.

Success Criteria • I can name the three different types of skeletons. • I can explain the pros and cons of different types of skeletons. Skeleton

What do you associate with the word skeleton? Vertebrates and Invertebrates

The difference between vertebrates and invertebrates is simple!

Vertebrates have a backbone (spine)… …and invertebrates don’t

Backbone (spine)

vertebrate invertebrate Now let’s see if you can categorise animals as vertebrates or invertebrates. Vertebrate or Invertebrate Quiz! Dog

VertebrateVertebrate or InvertebrateInvertebrate Worm

VertebrateVertebrate or InvertebrateInvertebrate Dinosaur

VertebrateVertebrate or InvertebrateInvertebrate Human

VertebrateVertebrate or InvertebrateInvertebrate Fish

VertebrateVertebrate or InvertebrateInvertebrate Jellyfish

VertebrateVertebrate or InvertebrateInvertebrate Butterfly

VertebrateVertebrate or InvertebrateInvertebrate Types of Skeletons

A further classification of skeletons comes from if an animal has a skeleton and where it is.

All vertebrates have an endoskeleton. However invertebrates can be divided again between those with an exoskeleton and those with a hydrostatic skeleton. vertebrate invertebrate endoskeleton exoskeleton hydrostatic skeleton

What do you think the words endoskeleton, exoskeleton and hydrostatic skeleton mean? Endoskeletons

Animals with Endoskeletons are endoskeletons have lighter than skeletons on the inside exoskeletons. of their bodies.

As the animal grows so does their skeleton. Exoskeletons

Animals with Watch the following exoskeletons have clip to see how they their skeletons on shed their skeletons the outside! (clip the crab below).

Exoskeletons do not grow with the animal. Therefore the animal has to shed its skeleton and produce a new one! Hydrostatic Skeletons

Animals with All animals with hydro- hydrostatic skeletons static skeletons are don’t actually have invertebrates. any bones!

Instead these animals have a fluid-filled compartment in their body called a coelom. Skeleton Types

endoskeleton exoskeleton hydrostatic skeleton

Can you think of an example of an animal with an exoskeleton, endoskeleton or hydrostatic skeleton? Sorting Skeleton Types Pros and Cons of Different Skeleton Types

Type of Skeleton Pro Con

Endoskeleton

Exoskeleton

Hydrostatic Skeleton

Grows with the body Does not grow with Cannot lift objects More protection for the body Muscles are less the body Body is more flexible flexible Aim • I can sort animals based on their skeletons.

Success Criteria • I can name the three different types of skeletons. • I can explain the pros and cons of different types of skeletons.